Method of casting



3 Sheets-Sheet l C. WESSEL METHOD OF CASTING SCI Filed Jan. 16, 1939 Izzeza Z31" Cari fleasei June 30, 1942.

HF HHH h l l l l U" H l June 30, 1942-. c. WESSEL 2,287,848

METHOD OF CASTING Filed 1939 s Sheets-Sheet 2 June 30, 1942. c. w EssELMETHOD OF CASTING Filed Jan. 16, 1939 3 Sheets-Sheet 3 Q NQ Q E NWN @NNNfiaVemZ'ar: Carl flesael Patented June 30, 1942 METHOD or CASTING' CarlWessel, Chicago, 111., assignor, by mesne assignments, to Carl Wesseland Lew W. Cleminson, both of Chicago, 111., trustees ApplicationJanuary 16, 1939, Serial No. 251,092

9 Claims. (Cl. 22-57) The present invention relates to methods ofcasting, and is particularly concerned with methods for producing bettercastings and better metal stock of various shapes more efiiciently andmore economically than can be done by the methods and apparatus of theprior art.

One of the objects of the present invention is the provision of animproved method of casting metal, utilizing refractory or metal molds,and filling the mold by gravity of the liquid metal in such manner thatthe complete filling of the mold is effected and the shinkage is avoidedby the continuous application of liquid metal under pressure, due togravity head, while the casting is cooling from its most remote endtoward the filling gate.

Another object of the invention is the provision of an improved methodof casting by means of which extremely thin sections may be made and bymeans of which the freezing of a part of the metal during the pouringprocess, commonly referred to as blow-holes, may be eliminated.

Another object of the invention is the provision of an improved methodof casting which produces an absolutely solid casting and produces ahigh degree of uniformity of crystal structure of the casting, and whichis also economical in its operation.

Another object of the invention is the provision of an improved methodof casting which avoids the contamination of the metal by filling themold without the liquid metal coming in contact with any air except thatsmall amount which is present in the mold.

Another object of the invention is the provision time, so that thecongelation of the metal may be accomplished while pressure is applied.

Another object of the invention is the provision of improved methodswhich are not only adaptable for individual casting and small plants butfor mass production.

Another object of the invention is the provision of an improved methodof producing sheets, strips, and stock shapes of metal, by meansof whichmuch costly rolling and annealing equipment may be eliminated, and bymeans of which stock shapes thin enough and possessing the necessaryhomogeneity for finishing and rolling purposes may be made, therebyreducing the cost of production and capital required for equipment.

Another object of the invention is the provision of improved castingsand methods for producing castings, by means of which shrinkage, flaws,and the formation of pipes and shrinking strains are eliminated, andcastings of uniform crystal structure may be produced at a mini-' mumcost.

Another object of the invention is the provision of an improved castingmethod which permits the melting and casting of the metal under reducedair, or controlled air conditions as required by the metal used.

Other objects and advantages of the invention will be apparent from thefollowing description and the accompanying drawings, in which similarcharacters of reference indicate similar parts throughout the severalviews.

Referring to the three sheets of drawings which accompany thisspecification,

Fig. 1 is a diagrammatic top plan view of a plurality of meltingfurnaces arranged for discharge into a centrally located ladle;

Fig. 2 is a similar view of a modified furnace and ladle arrangement;

Fig. 3 is a horizontal sectional View, taken on the plane of the line 33of Fig. 4, showing the structure of the ladle of Figs. 1 and 2;

Fig. 4 is a vertical sectional view, taken on the plane of the line 44of Fig. 3', looking in the direction of the arrows, showing thestructure of the ladle and the closely associated part of the mold;

Fig. 5 is a fragmentary sectional view of a modified form of connectionbetween the ladle and the mold, which may be utilized in Fig. 4;

Fig. 6 is a fragmentary elevational front view of the front part of theladle and conveying mechanism for supporting the molds in pouringposition.

Referring to Figs. 1 and 2, these are diagrammatic arrangements of aplurality of furnaces, shown in connection with a ladle of the typeillustrated in Figs. 3 and 4.

According to my method of operation in a foundry of suitable size, theladle 20 is provided with an insulating lining 2| and is adapted toreceive within its chamber H a suitable supply of molten metal forcontinuous casting operation.

The ladle 20 is a fixed ladle, and by means of its insulating lining 2|it maintains the metal at a suitable high degree of temperature forcasting operations the metal being discharged from the dischargeaperture 23 at the lower part of the ladle 20.

The furnaces 23-26 may be arranged in a circle about the upper part ofthe ladle 20, that is, on an upper floor, in such manner that eachfurnace may have its discharge conduit 21 of equal length to those ofthe other furnaces, and the furnaces are to be periodically charged witha batch of metal to be melted and successively discharged into the ladle20.

Different numbers of melting furnaces may, of course, be employed, thefurnaces preferably being of the rotating tilting type. For example, iffour furnaces are employed, a, batch might be discharged into the ladleevery fifteen minutes, the capacity of each furnace being about 250pounds per hour; while, if three furnaces were employed, a batch wouldbe discharged every twenty minutes. Under these conditions the capacityof the ladle might be approximately 1200 pounds or two cubic feet, andthe inner measurements of the ladle might be, for example, ten inchesinner diameter by thirty inches high.

The temperature of the metal discharged from the furnaces might beapproximately 2200 degrees F., and the temperature of the metal in theladle might be slightly lower, but need not vary more than about 200degrees F., as the heat of the metal in the ladle would be continuouslyreplenished by the periodic discharge into the ladle of hotter metalfrom the furnaces.

Each furnace is preferably provided with a rotating discharge spout 21,and the ladle or reservoir 20 is preferably provided with a suitablecover, which is removable, so that the metal is enclosed from the timeit is melted in the fur nace and during its discharge into the ladle andduring its discharge from the ladle into the mold, as be will furtherdescribed.

A cleaning of the metal is effected in the furnace before the pouringoperation by scraping out the dross and slag, with the furnace almost inlevel position, the scraping being effected through a discharge opening,

The melting may then be accomplished under reduced air and controlledconditions.

In the example of a furnace and ladle proportions cited, the head ofpressure might vary from full head in the ladle to half head during mostof the days casting. At the end of the days run, the reduced head, fromone-half to zero in the ladle, would be utilized for the casting ofrelatively small molds, which would not require as much gravity head asthe larger castings. The total capacity per day for an eight hour day ofcasting would be approximately 7,000 pounds.

As the practice of the method may be made more clear by reference to oneexample of the apparatus, I shall now describe in full one form ofapparatus which may be used for practicing the invention. i

Referring to Fig. 1, each of the melting furnaces 2326 is, of course,provided with a suitable heating device, such as a gas or oil burner,

and may be provided with a motor for rotating I conduits 3|, 35 and 35,31 are jointly to conduits 38, 39 respectively. In this case the lengthsof the eonduits for all of the furnaces are not equal,

ijito the discharge conduits 34-31, and the two but by means of the useof. a suitable refractory lining for the metal jacketed conduits 34-39the excessive loss of heat can be practically elimi nated andpractically the same discharge temperature secured for the batch fromeach furnace,

In the event the end furnaces 30 and 33 give evidence of slightlygreater cooling of the batch as it discharges down the elongatedconduits 3|, 38 and 31, 39, the end furnaces can be operated at slightlyhigher temperatures, to effect equalization of the temperature of thebatches discharged into ladle 20, which is similar in construction tothe ladle or reservoir 20, previously described.

Referring to Figs. 3-6, these are detailed illustrations of thestructure of the reservoir or ladle for melted metal and thearrangements for filling molds from this reservoir.

In Figs. 3 and 4 the ladle, which is indicated in its entirety by thenumeral 20, may have its interior insulation 2| formed in a plurality oflayers, the layers comprising, respectively, the inner refractory 40,the firebrick H and the rock wool or asbestos flber insulation 42.

The ladle 20 is preferably supported upon a suitable concrete foundation43 and may have its external metal jacket 44 built up of a multiplicityof metal sections 45-5l. These metal sections are in the form of endlessmetal bands of cylindrical shape, each successive section beingsupported upon the one below it so that the ladle can be built to anydesired height.

The metal jacket sections 455l are given additional support and held inalignment with each other by a plurality of vertically extending eyebeams 5255 (Fig. 3), which are preferably equally spaced about theperiphery of the metal jacket 44, extend axially thereof, and arelocated in contact with the external cylindrical surface of the jacketsections l5.-5l.

At each joint between the jacket sections there is a metal band 58-5l,and each metal band may be of similar construction to those shown inFig. 3, The metal bands 58-5I are bent to substantially partiallycylindrical form, and are long enough to encompass that portion of theperiphery which is located between the flanges of a pair of eye beams52-55. Any number of eye beams may be employed, but in a furnace of thesize mentioned above I consider four eye beams sufficient, and the metalbands SI, for example, contact the external surfaces of the sections 50and 5| of the jacket 44 throughout the major portion of their length,and are bent outward at 62 or provided with an offset 62 at each end soas to engage outside the inner flange 63 of the eye beams.

The band BI is also provided with an attachment flange 54 extendingradially at each end and adapted to engage the web 65 of the eye beam 54or 55, and the attachment flanges 54 are provided with apertures forreceiving the screw bolts 58, which pass through the attachment flangesB4 and through the web 65, and secure two of the attachment flanges ofthe bands 56-6l to each web.

The bands 56-6| are slightly shorter in length than the spaces betweenthe webs of the respective eye beams 54, 55 so that there is a toleranceto be taken up by means of the bolts 56, which draw the bands tightlyabout the metal sections 45--5l the jacket 44 and assure the securementof these bands against vertical movement due to the frictionalengagement between the bands and the metal sections.

Ihe ladle also comprises an iinner metal shell of similar constructionto the metal shell N, or the inner metal shell may comprise the simpleannular bands of metal, such as steel, mounted,

as Amosite, glass wool, or quartz wool, for the purpose of conservingthe heat in the ladle.

Inside the shell 10, the ladle 20 is provided with the layer 4| offirebrick, molded to fit together to form a wall which is annular inplan, and the firebrick preferably have their joints overlapping thejoints between the sections of the inner shell 10. For example, if thefirebrick are also one foot high, then this also facilitates thebuilding of various sizes of ladles or reservoirs which differ in heightby a foot.

The innermost layer of insulation comprises the refractory lining 40,which consists of a refractory composition that is smooth but notglazed, and which may be treated with flux or charcoal to prevent themetal from sticking to it.

The composition may include metal dioxides, clay, and feldspar, and suchrefractory linings may be made absolutely smooth so that the metal inthe reservoir can be kept clean.

A de-oxidizer compound can be kept on top of the charge in the reservoiror ladle 20 for the purpose of preventing any air contamination.

The refractory lining 40 is also in the form of peripheral sections,which, for example, may be a foot high, and all of which fit togethersmoothly to form the cylindrical reservoir chamber 1| for receiving themolten metal. This chamber is substantially cylindrical in shape at itsuppermost portion, such as, for example, the sections 12, 13, 14, or butat its bottom the chamber 1I tapers in diameter and is curved laterallytoward the discharge port 23. Thus the section 18 of the ladle chamber1I tapers from the initial diameter to approximately half the diameter,and extends toward the left in Fig. 3, in a streamlined curve. Therefractory blocks 11 adjacent this section are, of course, suitablyformed for this purpose.

The refractory blocks 18 of the lowermost sec tion have formed in them,when assembled, a continuation 19 of the tapered throat 18, which tapersstill farther along smoothly curved lines toward the reduced conduit 80in the refractory block 8| at the side wall of the ladle.

The metal jacket section 48 is provided with an enlarged aperture 82 forreceiving the refractory block 83, which may be cylindrical in form, and

which is provided with the discharge aperture 23, forming a continuationof the conduit 80.

The refractory block may be housed in a cast metal fitting 84, (Fig. 4),which is provided with an inner curved surface 85, and peripherallyextending fianges 86, 81 fit against a metal 4 band surrounding the wallof the section 86,- to which the flanges B6, 81 are bolted by means ofthe screw bolts 88, which have their threaded ends projecting outwardfrom the shell 46.

The fitting 84 may be built up in the form of a plurality of metalsections 90, 9|, 92, bolted or otherwise secured together, but theexternal portion 92 thereof is provided with laterally proeach other andin straight lines so that the flanges 91, 98 carried by the mold may beslidably mounted in the grooves 95, 98. Each-of the molds IOU-I05 maycomprise a metal lining and an external metal jacket I08 formed of twosimilar halves I01, I08 fitting together.

In other cases the jacket halves I01, I08 are lined with an inner layerI09, IIO of, smooth high-temperature -resistant and heat-insulatingrefractory, previously mentioned, which is used to line the innermostchamber 1| of the ladle, and the refractory sections I09, N0 of the moldhave the casting cavity III formed in them, and are separable at thesame join't II2 as the metal halves I01, I08 of the jacket I08. For thepurpose of illustration, the mold IIII is illustrated with a jacketcomprising two separable sections which are clamped or bolted togetherin any suitable way, preferably by means of pivoted bolts and wing nutsso that the molds may be removed quickly at the proper time. However,the molds may be made of any number of sections suitable to the natureof the shape of the casting so as to facilitate the removal of the moldfrom the casting as soon as it has congealed, without breaking any partof the casting.

The proper number of sections for a jacket or refractory lining of amold will be evident to any one skilled in the art of molding.

The present molds are adapted to be used over and over again, and arepractically indestructible. They are also preheated before use, and aremaintained in a heated condition by reuse, the number of molds beingadapted to the continuous operation of the machine by the use of a moldpractically as soon as it has been removed from one congealed castingwhich is still at a highly heated condition.

The refractory sections of the mold are formed with the semi-cylindricalgrooves H3, I, which together form an aperture or conduit that m creasesin size gradually as it extends downwardly and laterally, and theaperture II8 of this conduit II5 fits the discharge aperture 23 of theladle.

The metal jacket I08 of each mold has a diagonallydownward and laterallyextending formation which is adapted to be secured to the guide fittingI I1, having the flanges 91, 98 previously mentioned. This guide fittinghas a pair of outwardly extending fianges I I8 and a pair of downwardlyand upwardly extending flanges H9, and is provided with set screws I20for securement to the mold.

It will be noted that in Fig. 4 the mold IIII, which is for a relativelyfiat casting, extends diagonally upwardly. This is for the purpose ofpermitting the filling of the mold by the flowing upward of the meltedmetal in the mold, without any splashing or formation of drops.

It is contemplated that no special gates will be required for thedischarge of the air in the mold, as the air may leak out between thetwo halves of the refractory lining and metal jacket of the mold, whichare fitted closely enough to mold the casting with practically no fin,but still permit the escape of air.

It will be noted that the reservoir or ladle 20 isformed with adownwardly and laterally extending discharge conduit, which tapersgradually to its smallest section at the mouth I2I of the castingcavity. The molds may thus be slidably.

straight line, so as to support a multiplicity of molds, as shown inFig. 6. In some embodiments of the invention the ladle may be providedwith a plurality of discharge openings for an equal number of molds.

In some plants the molds may be shoved past the discharge aperture 23 ofthe ladle by hand. As soon as the aperture II6 of the mold has passedthe discharge aperture 23, the further discharge of melted metal isarrested by the fact that the flat surfaces on the face I22 of therefractory of the mold cover up the discharge aperture 23.

If desired, a suitable steel die may be provided at this face I22 forshearing off any metal which may have congealed.

In the practice of my method, the metal, which may be congealedslightly, will still be capable of being sheared off at this time. I

When the molds are shoved into place by of the stop member out of itsoperative position will permit the progress of the mold from the castingposition to a position further on in the guides of the guide fixture 84.

In other embodiments of the invention a suitable driving mechanism maybe provided, such as, for example, the frame members I (Fig. 6) whichsupport a driving rack I3I that is slidably mounted by means of the pinsI32 in slots I33 below the molds.

This rock may be spring-urged toward the right by means of a tensionspring I34 engaging a pin on the rack, and having its opposite endsecured to a frame member. The rack is provided with a plurality ofpawls I35I4II. Each pawl I35-I46 is pivotally mounted upon a pin HI andengages a stop member I42, toward which it is pulled by means of aspring I43.

The rack bar I3I also has a driving pin I suitably located to be engagedby the shoulder I49 carried by a rotating drive wheel I50 mounted onshaft I5I.

The operation of this step-by-step mechanism is as follows: Shaft I5Imay rotate at a constant speed, which is determined by the length oftime required for the making of one casting. This time will besufficient, as hereinafter more fully described, to permit not only thefilling of the mold with melted metal, but the continued application ofmelted metal under gravity head to the mold while the casting congealsfrom its outermost point. inward toward the supply of metal in thereservoir.

During this congelation the shrinkage of the casting is taken up by thesupply of additional metal from the molten end of the casting, and thelast part of the casting to freeze should be that adjacent the mouth I2Iof the mold. Thus the actuating shoulder I49 performs a rotation in apredetermined time, which is determined by the characteristics of thecasting or mold and by the time required to carry out my process.

When the shoulder I49 engages the pin I45, it causes the rack I3I tomove to the left by an amount equal to the length of a slot I33, whichis suiiicient to move one mold IIII from the position which it occupiesin Fig. 5, in registry with the discharge aperture 23, and to bring thenext mold I02 into that same position. Thereafter the shoulder I49 slipsoff and passes the pin I45, due to the rotation of the wheel I 50, andthe spring I34 returns the rack I3I, during which movement all of thepawls I35-I4II are adapted to slide past the molds which are immediatelyto the right of each pawl.

The pawls are then in position to engage and actuate these molds whenthe rack has reached the position of Fig. 6 again. Thus the mechanism isadapted to effect the movement of the molds in a step-by-step manner andto permit the molds to remain in casting position for a predeterminedlength of time.

Referring again to Fig. 4, the ladle is preferably provided with a fixedcover member I60, which may comprise a metal jacket I6I having anexternal cylindrical portion I62 and a flat end portion I63.

The Jacket I 6| may be bolted in place by means of the bolts I64 andflanges I65, I66. The jacket may have a centrally located aperture I61with a downwardly extending frusto-conical flange I68. The jacket islined with a flat block of refractory I 69 in the form of a disc havinga centrally located frusto-conical bore I10 fitting against the flangeI68.

This aperture I10 serves as a filling opening for the reservoir or ladle1|, and it in turn may be closed by a movable cover member III, whichhas a metal 'jacket I12 anda refractory lining I13 retained by means ofa frusto-conical flange I14. The movable cover I1I fits in the bore I61and produces an effective closure, due to the engagement of the metalflanges I68 and I14.

The movable cover "I may be provided with a centrally located airaperture I15, communicating with a counterbore I16 for receiving aconical valve member I11. The valve member I11 has a stem I18 guided inan aperture in the jacket I12 and urged to closed position by a springI19. The stem I 18 has a transverse pin I engaging in a slot in the endof a lever I8I.

The lever I8I is pivoted on the bracket I82 and provided at its oppositeend with a pull rod I83 slidably mounted in a guide fixture I84 andprovided with a ball counter-balance I85. By means of a pull on the rodI83 the operator may regulate the admission of air to the chamber 1| ofladle 20, and thus control, at least in some measure, the discharge ofmetal from its lower end.

Thus the pull rod I83 would be pulled whenever the mold was in front ofthe discharge aperture of the ladle, and the actuation of the rod may begradual, in order to permit the filling of the mold without anysplashing, or to reduce the impact which results when the molten metalflowing into the mold reaches the end of the mold.

Referring to Fig. 5, this is a modification in which the conduit I I5 isprovided with a butterfly valve 216 for controlling the flow of themetal into the mold.

This valve may be so constructed that its actuating shaft may bewithdrawn, and that portion of the conduit II5 surrounding it may beseparated when the mold is separated, so that the metal in the conduitII5 may be removed from the conduit with the valve 210, and a new valvesubstituted when the mold is again used.

My method of casting is briefly described as follows: When a ladle ofthe type described is used, the ladle is constantly supplied with newbatches-of molten metal, from which all dross or scum have been removedin the furnace, and this metal is supplied to the ladle without exposureto the air, so far as possible.

A de-oxidizer compound may be kept on top of the charge, to prevent aircontamination.

The molten metal is kept in the ladle, which is lined with smoothrefractory, suitably treated with flux or charcoal, to prevent the metalfrom sticking to it, and suitably insulated, so that the metal may bemaintained at a high temperature, with a minimum fluctuation oftemperature between batches.

When ordinary castings are to be made, the mold is made of a similarsmooth refractory capable of retaining the heat, and providing heatinsulation for the casting, and the mold is pre-heated either by apreheating operation or by being used over and over again, immediatelyafter a previous casting operation.

The mold and the ladle have their entry and discharge openings andconduit for the metal smoothly tapered along stream lines so that therewill be no splashing and the least amount of agitation of the metal.

The mold may be lined with metal inside the refractory to reducebreakage of molds and improve castings and whencasting with certainmetals, I use metal molds where it is economical.

The mold is tilted upward from its filling opening so that metal runninginto the mold cannot drop down to the end of the mold and splash. Afterthe mold opening is placed in registry with the discharge opening of theladle, the molten metal is permitted to well up into the mold, its levelconstantl rising, until it completely fills the mold.

During this time the metal is still molten and maintained heated becauseof the insulating character of the refractory mold or the preheating ofthe mold.

The mold may, in the case of relatively large castings, be provided withapertures for the issuance of the air, but in most cases the air willleak out between the halves of the mold, and the molds in such case willnot need risers.

The method may be practised with all types of metals. The thickness ofthe refractory in the mold and in the ladle are proportionate to thebulk of the metal in the casting or the bulk of the metal in the ladle,respectively.

After the mold has been filled, it is then maintaiaed in the sameposition, withthe metal of the ladle pressing into the mold, due to thehead of the metal in the ladle, until the metal has solidified in themold.

During this operation the pouring end of the mold is the hottest, andthe end farthest from the ladle is the coolest. There is a heat gradientextending from the ladle outward to the extreme end of the mold. As themetal solidifies, it begins to solidify at the extreme end of the mold,away from the ladle, and gradually solidifies downward toward thefilling opening of the mold. During this operation any shrinkage istaken up by the supply of additional melted metal, due to the head ofthe metal in the ladle.

There will be no flaws or pipes, nor will the casting be subjected tostrains due to unequal contraction. The entire mold will be filled, andthe casting will correspond more closely to the shape of the mold thanwith the methods of the prior art.

After the casting has solidified in the mold down to the filling openingof the mold; the further flow of metal into the mold is cut off bysliding the mold sidewise so that the stream of metal is sheared off. Ifit has solidified down to the point of shearing, it can still be sheared01?, due to its relative softness at such a high temperature, and thedischarge aperture of the ladle is closed by a flat surface on the endof the mold.

The next mold continues to close this discharge opening b a similar flatsurface until its filling opening comes in registry with the dischargeopening of the ladle, after which the filling of mold is again resumed.

The mold, which has been filled and removed from its ladle, has itsparts separated, and the casting is removed at a proper time, which isdetermined by the character of the casting. This enables the use-of themold over again while it is still in a heated condition, and the castingmay contract as it cools, without producing any strains on the mold orbreaking the mold. The casting may contract more freely than if it wereleft in' the mold.

Castings may thus made to closer tolerances, and the present methodmakes sure the elimination of flaws because of the constant applicationof liquid metal under pressure to the molten side of the casting, as thecasting solidifies. There is no chance of getting drops of metal in themold, as the metal wells up into the mold, due to the tilt of themoldwith respect to its filling opening.

Such drops frequently happen in the. casting methods of the prior art onaccount of splashing or agitation, and such drops solidify on the waydown into the mold, in the devices of the prior art. This cannot happenaccording to my method.

One of the most important features of the method is the freezing of themetal last at the mouth of the mold and at the beginning of thefreezingat the point farthest away from the mouth of the mold. In somecastings gates may be provided at the most remote point of the mold. Arim around the casting may usually be avoided because such heavypressures are not employed in my method as in die casting.

The castings, after removal from the mold, are preferably subjected tothe uniform foundry temperature of approximately 65 degrees F., and keptout of draft. They could also be quenched in water, if desired, but arepreferably cooled uniformly by being subjected to a moderate and uniformcooling temperature so that they will contract in proportion, everywherein the casting.

While I have illustrated a preferred embodiment of my invention, manymodifications may be made without departing from the spirit of theinvention, and I do not wish to be limited to the precise details ofconstruction set forth, but, desire to avail myself of all changeswithin the scope of the appended claims.

Patent of the United States, is:

l. The method of casting which comprises melting the casting metal in aplurality of melting furnaces arranged to provide batches of moltenmetal for discharge into a ladle at regular intervals to maintain thehead of metal in said ladle at predetermined height and to maintain thehigh temperature of metal in said ladle, maintaining the temperature ofthe metal in said ladle by insulation and by periodic supply of hottermetal, discharging the molten metal from said ladle at its lower endlaterally and upwardly into a mold having a cavity and a downwardlydirected filling opening, the molten metal Welling up into said mold tofill the mold without splashing, and with a minimum contact of moltenmetal to the air in the mold, maintaining the temperature of the castingmetal in the mold cavity by insulation of said mold, and keeping themold in connection with the supply of molten metal while the metalsolidifies in the mold, beginning at a point remote from the fillingopening, downward to the filling opening, whereby the shrinkage is takenup by the supply of additional molten metal from said ladle until thetemiined temperature from said container directly into a mold, through arelatively large stream-lined discharge opening, the transfer of metalfrom ladle to mold being from a point below the free surface of themolten metal in the container at the time of transfer, and said moldhaving its cavity extending upward from said discharge opening at thetime of transfer, the transfer of the metal from container to moldtaking place in the form of a gradual welling up of a solid stream ofmetal in the mold without splashing or spurting or separation of moltenmetal from the main body of said stream until the mold is filled bygravity head, and thereafter maintaining a gravity head pressure on saidmold in excess of the head of metal in said mold for a predeterminedperiod of time to supply metal to the interior of the casting duringcongelation and shrinkage, the casting solidifying from a pointfarthermost from said discharge opening down toward said dischargeopening.

3. The method of casting which comprises providing a supply of moltenmetalin an insulated container, and maintaining the temperature of saidmetal at a predetermined temperature, transferring molten metal at saidpredetermined temperature from said container directly into a mold,through a relatively large streamlined discharge opening, the transferof metal from ladle to mold being from a point below the free surface ofthe molten metal in the container at the time of transfer, and said moldhaving its cavity extending upward. from said discharge opening at thetime of transfer, the transfer of the metal from container to moldtaking place in the form of a gradual wellingup'of a solid stream ofmetal in the mold without splashing or spurting or separation of moltenmetal from the main body of said stream until the mold is filled bygravity head, and thereafter maintaining a gravity head pressure on saidmold in excess of the head of metal in said mold for a predeterminedperiod of time to supply metal to the interior of the casting duringcongelation and shrinkage, the casting solidifying from a pointfarthermost from said discharge opening down toward said dischargeopening, and removing said casting from its mold promptly aftersolidification of the metal of the casting down to said dischargeopening.

4. The method of making metal castings of homogeneous uniform-grainedstructure which comprises melting a supply of clean metal in a pluralityof furnaces arranged adjacent a heat ofthe metal directly into apreheated metal mold constructed of a metal of higher melting point thanthe casting metal, said mold extending upward from its filling opening,whereby the metal wells upward into the mold without splashing due tothe gravity head of metal in the, ladle until the mold is filled,maintaining the gravity head on the metal in the mold thereafter inexcess of the head of metal in said mold for a predetermined period oftime to supply metal to the interior of the casting during congelationand shrinkage, the casting cooling naturally by radiation and conductionand solidifying from a point farthermost from said discharge opening andinwardly from the sides of said mold down toward the discharge openingand stopping the application of pressure head to said casting when thecasting has congealed just past the filling opening of the mold.

5. The method of making metal castings of homogeneous uniform-grainedstructure which comprises melting a supply of clean metal in a pluralityof furnaces arranged adjacent a heat insulated ladle, to a predeterminedelevated temperature, maintaining a supply of said melted metal in theheat insulated ladle at a predetermined lower temperature byperiodically discharging metal successively from said furnaces into saidladle, discharging the molten metal from said ladle at a point below thefree surface of the metal directly into a preheated metal moldconstructed of a metal of higher melting point than the casting metal,said mold extending upward from its filled opening, whereby the metalwells upward into the mold without splashing due to the gravity head ofmetal in the ladle until the mold is filled, maintaining the gravityhead on the metal in the mold thereafter in excess of the head of metalin said mold for a predetermined period of time to supply metal to theinterior of the castingduring congelation and shrinkag the castingcooling naturally by radiation and conduction and solidifying from apoint farthermost from said discharge opening and inwardly from thesides of said mold down toward thedischarge opening and stopping theapplication of pressure head to said casting when the casting hascongealed just past the filling opening of the mold, the said ladle andmold being closed to minimize the oxidation of metal at the freesurface, and the mold being heat insulated to eliminate the possibilityof cooling by extraneous influences.

6. The method of making metal castings of' homogeneous uniform-grainedstructure which comprises melting a supply of clean metal in a pluralityof furnaces arranged adjacent a heat insulated ladle, to a predeterminedelevated temperature, maintaining a supply of said melted metal in theheat insulated ladle at a predeter- 'mined lower temperature byperiodically diswells upward into the mold without splashing due to thegravity head of metal in the ladle until the mold is filled; maintainingthe gravity head on the metal in the mold thereafter in excess of thehead of metal in said mold for a predetermined period of time to supplymetal to the interior of the casting during congelation and shrinkage,the-casting cooling naturally by radiation and conduction andsolidifying from a point farthermost from said discharge opening andinwardly from the sides of said mold down toward the discharge openingand stopping the application of pressure head to said casting when thecasting has congealed just past the filling opening of the mold, andseparating the casting and mold promptlyafter solidification to permitthe shrinkage of the casting without constraint.

'7. The method of making metal castings of homogeneous uniform-grainedstructure which comprises melting a supply of clean metal in a pluralityof furnaces arranged adjacent a. heat insulated ladle, to apredetermined elevated temperature, maintaining a supply of said meltedmetal in the heat insulated ladle at a predetermined lower temperatureby periodically discharging metal successively from said furnaces intosaid ladle, discharging the molten metal from said ladle at a pointbelow the free surface of the metal directly into a preheated metal moldconstructed of a metal of higher melting point than the casting metal,said mold extending upward from its filling opening, whereby the metalwells upward into the mold without splashing due to the gravity head ofmetal in the ladle until the mold is filled, maintaining the gravityhead on the metal in the mold thereafter in excess of the head of metalin said mold for a predetermined period of time to supply metal to theinterior of the casting during congelation and shrinkage, the castingcooling naturally by radiation and conduction and solidifying from apoint farthermost from said discharge opening and inwardly from thesides of said mold down metal directly into a preheated mold constructedof material of higher melting point than the casting metal,said moldhaving its major axis extending upward from its filling opening at anangle which is ,oblique with respect to the free surface of the moltenmetal, whereby the metal wells upward into the mold in a solid stream ofmetal without splashing orspurting or separation of molten metal fromthe inain body of said stream, with its free surface progressing upwardfrom the filling opening to the top of the mold, until the mold isfilled by gravity head, and thereafter maintaining a gravity headpressure on the metal in said mold by means of the molten metal in saidcontainer, in excess of the head of the metal in said mold for apredetermined period of .time to supply metal to the interior of thecasting during congelation and shrinkage, the casting cooling andsolidifying from a point farthermost from said discharge opening, and

inwardly from the sides of said mold down tof ward the dischargeopening, and causing the toward the discharge opening and stopping the8. The method of making metal castings having a homogeneousuniform-grained structure, which comprises providing a supply of cleanmolten metal in a heat insulated container, discharging the molten metalfrom said container at a point below the free surface of the moltencessation of the application of pressure to said, casting when thecasting has congealed to a pre-- determined point.

9. The method of making metal castings having a" homogeneousuniformrained structure, which comprises providing a supply of cleanmolten metal in a heat insulated container, discharging the molten metalfrom said container at a point below the free surface of the moltenmetal directly into a preheated mold constructed of material of highermelting point than the casting metal, said mold having its major axisextending upward from its filling opening at an angle which is obliquewith respect to the free surface of the molten metal, whereby the metalwells upward into the mold in a solid stream of metal without splashingor spurting or separation of molten metal from the main body of saidstream, with its free surface progressing upward from the fillingopening to the top of the mold,

-until the mold is filled by gravityhead, .and thereafter maintaining agravity headpressure on the metal in said mold by means of the moltenmetal in said container, in excess of the head of the metal in said moldfor a predetermined period of time to supply metal to the interior ofthe casting during congelation and shrinkage, the casting cooling andsolidifying from a point farthermost from said discharge opening, andinwardly from the sides of said mold down toward the discharge opening,and causing the cessation of the application of pressure to said castingwhen the casting has congealed to a predetermined point, and removingsaid casting from its mold promptly after solidification of the metal ofthe casting to permit the casting to contract without the restraint ofthe mold.

CARL WESSEL.

